conform to the Mercurial custom of lowercase messages ...and while at it, use the more usual long form of "can't"

amend: use core mechanism for amend Evolve used its own code for amending. This was introduced before mercurial includes commit --amend. The evolve code is now older and buggier. So we just use the core cod when amend is called. Message of the temporary commit is different, all test hash changed \o/. Test change are been carefully checked.

amend: drop the deprecated note option We plan to get closer to the commit --amend implementation dropping this deprecated option helps.